0
mccordia

WS high altitude/glide degradation

Recommended Posts

Heyhey..

Couldnt find it in 'the archives' so here's my question.
Is there any information (be it a rough estemate or rough GPS data) about the glide ratio a wingsuit gets higher up at say 25.000 ft?

There have been a few awesome high altitude distance crossings (both in wingsuit or with wing) like Gibraltar/English Channel, but on both of those, no data (or even just video in some cases) was ever released, even though initialy it was promised in both cases. And at the moment Id be quite curious to see how much our flight performance degrades in the thinner air, up high.

We're working on a project here, and Im trying to get a rough estemate of the needed altitude for what we have in mind, distance-wise.

Say you're normaly cruising along at roughly 2.0 glide for a full skydive around 10.000 ft or so.
Anyone know what your glide would roughly be when you are at 25.000 ft?
JC
FlyLikeBrick
I'm an Athlete?

Share this post


Link to post
Share on other sites
You looking for exact numbers or ball park? I have (somewhere) the data from several 22k+ dives that might be of interest to you. PM me with what it is your doing and what you need.
"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

Share this post


Link to post
Share on other sites

Just a ballpark figure would be fine...glide at 25k, 20k, 15k, 10k, 5k (excluding fatige, wind etc).

Just so I can take what we are currently flying distance-wise in a 2 way from 12K, and do a rough estemate on what the possible distance would be from 25k. We're not looking to set records or anything. We just need to see how much altitude we need to not get our feet wet, or do the gay thing and use our canopies to actually make it:P

JC
FlyLikeBrick
I'm an Athlete?

Share this post


Link to post
Share on other sites
If you fly the same way in the same suite you'll glide the same distance just at a higher speed and therefore less time. So distance will be the same but time per thousand feet will be reduced.
I only trust two people in this world, one of them is me and the other one aint you.
Nicolas Cage as Cameron Poe in "Con Air"

Share this post


Link to post
Share on other sites
would be interesting numbers - i was looking at doing a wing suit dive from 25k over here in my SM1 - because of the new improved technology and more flight time we can achieve due to better build/designed suits i think any current longest flight record can be shattered by a long margin.

waiting to get our plane (king air) down to the coast again. where i live its 5k above sea level so it wont work.

~ time is ~ time was ~ times past ~

Share this post


Link to post
Share on other sites
Quote

here is the link of a former DZ.com article about that :

http://www.dropzone.com/cgi-bin/safety/detail_page.cgi?ID=592



With 12 km of freefall, and 20,5 km of distance. That roughly puts them at 1,7 L/D for 6 full minutes of flight.
If those numbers are correct, its should roughly be safe to say glide doesnt suffer too much at higher altitudes (though jetstream winds up high could be the reason for them flying further up high)

For the aviation experts around here...anyone know anything about airplane glide performance at lower and higher altitudes?
JC
FlyLikeBrick
I'm an Athlete?

Share this post


Link to post
Share on other sites
(though jetstream winds up high could be the reason for them flying further up high)



Yeah! If the rules called for them to do it from the opposite direction within a time frame like in land speed records, it would be fair to say they'd be flying backwards. I doubt they would make it back to the point on the ground below the exit point.

Share this post


Link to post
Share on other sites
there is no degredation at all, your indicated airspeed which is all that matters as far as lift and drag go is exactly the same as it is at sea level. your True airspeed on the other hand is very different. If your true airspeed was 120 mph at sea level at 25k in minus 20C you would be doing 185mph True!! unfortuatly you would have the decent rate to match it so you would glide exactly the same amount of distance in 1000 feet if you were in a no wind environment.
I only trust two people in this world, one of them is me and the other one aint you.
Nicolas Cage as Cameron Poe in "Con Air"

Share this post


Link to post
Share on other sites
Quote

Heyhey..

Couldnt find it in 'the archives' so here's my question.
Is there any information (be it a rough estemate or rough GPS data) about the glide ratio a wingsuit gets higher up at say 25.000 ft?

There have been a few awesome high altitude distance crossings (both in wingsuit or with wing) like Gibraltar/English Channel, but on both of those, no data (or even just video in some cases) was ever released, even though initialy it was promised in both cases. And at the moment Id be quite curious to see how much our flight performance degrades in the thinner air, up high.



Jarno, the Gibraltar project gps data is downloadable at http://www.frwd.fi/images/recordings/4/Estrecho_1_(Skydiving).fwd

to display it you need a frwd player available at same website. I think it can also be transferred to google-earth to judge it on map.

Vesa

"Fear is the path to the Dark side"
(Master Yoda)

Share this post


Link to post
Share on other sites
Quote

Borgy is spot on. L/D ratio stays the same.
Take care,
space



In theory it should.
L/D = Cl/Cd and Cl and Cd are only dependent on shape is Aero 101 thinking. Drag is made up of Shape dependent and Lift dependent components.

In practice, L/D is better in the lower atmosphere(BASE flight altitudes). However, it is not possible to say that this is because of the denser air alone.

Kris

Share this post


Link to post
Share on other sites
.............it is embarrassing to see that after heaving the ram air technology over 30 years, that after heaving planes over 100 years, paragliders, hanggliders and kites above our heads over 20-30 years, that after heaving the access to almost any source and finally after hoping that basic is clear... it is embarrassing to even question such Q..
Robert Pecnik
[email protected]
www.phoenix-fly.com

Share this post


Link to post
Share on other sites
Jarno,
It does not fly at less glide nor it flies less or higher than optimal.
Effect what often help us , and why base flights looks better is mostly, equipment, thermal weather condition and dedication of the flier (ground feedback) That is all. This was, I thought so clear.

embarrassing is to see that people here, who has higher interest in flying than average jumper questioning such clear fact which saying: Air dents has nothing with glide...

Share this post


Link to post
Share on other sites
Back in October 2005 I went from 30000ft with a wingsuit, we managed data logging which gave an average or 53mph descent rate, up top I was in mid 40's for some time, first minute or so, lower its starts to speed up as you suffer fatigue in arms from position and cold.

Tha data logging is difficult as the temperature tends to screw a lot of equipment. So what i can tell you is from exit to deployment I went 8.5 miles, however that was with a 80kt head wind coming at us which obviousoly changed as we got lower.

I am planning another littlwe sortie to High altitude, however there are some limits to how high we can go, apart from getting airspace clearnace the right gear and support crew. The physiology of high altitude jumps can become pretty serious once your up to 40. The time of useful conscious if not pressure breathing is around 15 seconds at 40,000ft so you need to be on the ball and have a good team and gear. Luckily I had an excellent HALO jump master and a worldclass scientific company behind me with all preparation and altitide trainign facilities including chamber.

The temp and windchill is a mother but the view is pretty good. I had an exhasut valve freeze about 15 seconds out of the door and had to break the seal with facial contortions, Not impossible but a nuisance when your focussing on position and maintaining a heading.

I had twin thermal gloves with gortex liners and still at pull time good barely feel anything.

If you want any other info ask or Pm me.

Take care and have fun the view rocks.

Fraser
Dont just talk about it, Do it!

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

0